Improvement in



B. M. WILKERSON. Apparatus for Raising and Lowering Articlesof Furniture.

No.197,707. Patented Nov. 27, 18 77 ;PEIERS. Fkormumcammin, WASHINGTON. D

ATTOIRNEY.

UNITEDSTAT S Pn'i'nn'r OFFICE. I

BASIL. MJWILKERsON, on BALTIMORE, MARYLAND.

IMPROVEMENT. IN; APPARATUS FOR RAISING LAND LOWERINGARTICLES'0F FURNITURE.

' Specification forming part of Letters Patent No. 197,707, dated- November 27, I877; application filed November 14, 1877.

To all whom it may concern:

Be it known that I, BASIL M. WILKERSON, of the city of Baltimore, State of Maryland, have invented certain new and useful Improvements in Fmniture-Stands; and I hereby declare the same to be fully, clearly, and exactly described, as follows, reference being had to the accompanying drawings, in which- Figure 1 represents a vertical sectional view of my device; Fig. 2, a plan view of the same.

This invention has for its object to furnish a simple, ready, and efficient means of elevating the bodies of certain articles of furniture, such as dental or barbers chairs, tables, pho- 'tographic cameras, piano-stools, &c., and of retaining the said bodies in the positions to which they are raised.

To this end 1 construct my furniture-stand as follows, reference being had to the accompanying drawings.

A represents a metallic tube, closed at the bottom, and having an enlargement, a, at the top. B is a tubular plunger, fitting tightly within the tube A, and furnished at the bottom with apair of valves, D (I. The valve D is adapted to completely close the lower end of the tubular plunger B, but is considerably smaller than the interior of the tube A, the object of which construction will presently be evident.

In the valve D is fitted a small cone-valve,

cl, having a stem, 01. Upon this stem is a collar or pin, between which and the spider e e, at the bottom of the plunger, a spiral spring, 1", is fitted, whereby both valves are held to their seats. The plunger B is perforated with a line of holes, forming a rack, with which the gear-Wheel O engages. This latter is mounted upon a shaft, E, which has its bearings in the enlarged portion a of the outer tube, the said shaft carrying a ratchet, c, with which. a pawl, c, on the wheel 0 engages, and terminating in the ordinary square or polygonal end for the attachment of a crank. The valve-stem cl is attached to a rod, h, which is actuated by an eccentric, i, upon the shaft k, the latter having a handle, I.

The orifice in I the enlarged portion a of the outer tube is furnished with an annular bead, at, whose function will be presently described.

The upper end of the tube B is threaded, as

shown at m, for the attachment of the chairbody, table, piano-stool seat, or whatever article of furniture or machine is to be mounted upon the stand.

Legs of tasteful or ornamental design, which I have not considered it necessary to illustrate in the drawing, are attached in any co"nvenient way to the tube A.

The operation of the device is evident from the foregoing description. A suitable quan tity of a fluid, preferably some liquid not liable to attack or corrode the metal tube or plunger, such as oil or glycerine, is poured into the main tube to completely fill the portion A. The plunger B, being then inserted therein, as shown, may beraised by means of the pinion O and crank upon the shaft E, or even by a direct lift from the hands in case the article of furniture mounted upon the plunger is light, such as a piano-stool or camera.

It is evident that as the plunger is raised a vacuum is formed below it, causing the liquid to flow through the valves, which liquid constitutes the means of sustaining the plunger at any point to which it has been raised.

In order to lower it, it is only necessary to open the valve at the bottom of the plunger by means of the cam c on the shaft 70, and allowthe liquid to flow through the opening, as the plunger descends by its own weight.

The bead a serves to shed any liquid which is carried up in the perforations in the plunger back into the reservoir, instead of allowing it to run over the outside thereof. A pair or more of holes, 9, near the bottom of the plunger, afford a passage for the liquid when the rack is carried above the level in the reservoir.

It is obviously not essential that the 'plunger should fit the tube closely throughout its length. It is sufficient if the lower end of the plunger fits accurately in the tube and the upper hearing. In this case the bead a is close enough to prevent shaking. An ordinary leather cup or washer may be used at the lower end of the plunger, to insure a fluid-v tight fit. My object in using two valves, D d,

is to admit of a quick upward movement of the plunger, and a slower downward one, whereby danger of shock in descent is obviated.

voir a, the perforated plunger B, having valve I,

d, substantially as described.

3. In combination with the tube A and reser voir a, the tubular plunger B, pinion C, and crank-shaft E, substantially as described.

4. In combination with the hollow plunger B, the double valve'D d, as and for the pur pose described.

BASIL M. WILKERSON.

Witnesses:

FRANK GALT, R. D. WILLIAMS. 

